package com.darrenchan.leetcode;

/**
 * @Desc
 * @Author chenchi03
 * @CreateTime 2019-12-22 18:20
 */
public class Q63 {
    public int uniquePathsWithObstacles(int[][] obstacleGrid) {
        if (obstacleGrid == null || obstacleGrid.length == 0 || obstacleGrid[0].length == 0) {
            return 0;
        }
        int m = obstacleGrid.length, n = obstacleGrid[0].length;
        int[][] dp = new int[m][n];

        dp[0][0] = 1 - obstacleGrid[0][0];
        for (int i = 1; i < m; i++) {
            dp[i][0] = Math.min(dp[i - 1][0], 1 - obstacleGrid[i][0]);
        }
        for (int j = 1; j < n; j++) {
            dp[0][j] = Math.min(dp[0][j - 1], 1 - obstacleGrid[0][j]);
        }

        for (int i = 1; i < m; i++) {
            for (int j = 1; j < n; j++) {
                if (obstacleGrid[i][j] == 1) {
                    dp[i][j] = 0;
                } else {
                    dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
                }
            }
        }

        return dp[m - 1][n - 1];
    }
}
